In the fabrication of semiconductor devices such as integrated circuits, memory cells, and the like, a series of manufacturing operations are performed to define features on semiconductor substrates (“substrates”). During the series of manufacturing operations, the substrate surface is exposed to various types of contaminants. Essentially any material present in a manufacturing operation is a potential source of contamination. For example, sources of contamination may include process gases, chemicals, deposition materials, etch by-products, and liquids, among others. The various contaminants may deposit on the wafer surface in particulate form (or particles).
The surface of semiconductor substrates must be cleaned of substrate contaminants. If not removed, the devices within the vicinity of the contamination will likely be inoperable. Substrate contaminants may also affect device performance characteristics and cause device failure to occur at faster rates than usual. Thus, it is necessary to clean contaminants from the substrate surface in a substantially complete manner without damaging the substrate surface and the features defined on the substrate. The size of particulate contamination is often on the order of the critical dimension size of features fabricated on the wafer. Removal of such small particulate contamination without adversely affecting the surface and features on the substrate can be quite difficult.
In view of the foregoing, there is a need for an improved substrate cleaning technique to remove contaminants from substrate surface to improve device yield.